US pilots say flyers not told of 737 Max safety risks

Boeing (BA -1.4%) plunges as much as 4% after making fewer 737 deliveries than expected and news that the company had failed to advise pilots of new safety systems on the 737 MAX, which may have played a role in the recent Lion Air crash. Boeing hasn't yet officially commented on the reports.

"We are taking every measure to fully understand all aspects of this incident, working closely with the investigating team and all regulatory authorities involved", the company said in a statement by email.

"The bottom line here is the 737 Max is safe", Boeing Chief Executive Officer Dennis Muilenburg said Tuesday on Fox Business Network. The error Capt Thomas refers to involves a sensor which could erroneously indicate that the aircraft nose is dangerously high. In the meantime airlines, pilots, regulators and jet manufacturers have been frantically reviewing flight protocols and systems to ensure passengers on other 737 MAX8 jets are not put at risk.

Boeing reportedly warned airlines about the newly introduced feature and risks it hypothetically carries in a safety bulletin issued days after the tragedy, which points to the fact that pilots couldn't have been aware of the new computer mechanism and risks connected with flight control at the moment of the crash, shortly before and even immediately after it. And again, in certain failure modes if there's an inaccurate angle-of-attack sensor feeding information to the airplane, there's a procedure to handle that.

When Boeing designed its latest version of the 737, it added the new safety feature to combat a loss of lift, which is a leading contributor to the loss-of-control accidents that by far cause the most crash deaths around the world. It essentially tricked the system into ordering a sharp dive.

Investigators said the jet experienced problems on its last four flights - including, crucially, the flight that crashed, according to Soerjanto Tjahjono, the head of the National Transportation Safety Committee (KNKT).

The pilot of Flight 610 had more than 6,000 flying hours while the co-pilot had more than 5,000 hours, according to the airline.

On Monday, the US Federal Aviation Administration issued a follow-up directive confirming that the manual for the Max 8 needed to be updated to address this rare but unsafe sequence of events.

Nearly two weeks after the crash, authorities are still searching for the plane's cockpit voice recorder (CVR), which is believed to be buried under deep mud.

It is not clear whether the quick thinking of the pilot on that flight was relayed to the captain of the plane's final flight.

Investigators are already examining the flight data recorder (FDR) that was pulled off the sea bed, some 30 meters under water, on November 1. Likewise, erroneous air-speed indications, coupled with pilot errors, led to the crash of an Air France Airbus A330 over the Atlantic in 2009. "So the pilots keep putting the nose up and the plane keeps putting the nose down".

However, as training and documentation regarding this facility were excluded from the inductions to the new aircraft, the pilots of the Lion Air flight would not have stood a chance.